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Author Topic: Acceleration Settings  (Read 1769 times)

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Re: Acceleration Settings
« Reply #10 on: November 30, 2017, 07:07:46 PM »
Hi,
another small point worth bearing in mind, the smallest 2 flute mill in the list is 0.032" or 32 thou.
You are using 0.02"  20 thou. The larger 32 thou tool has 256% greater cross sectional area than what you are using
and will be much stronger as a result.

I used to use 16 thou (0.4mm) tools. My target is to produce pads with minimum separation of 0.6mm consistant with
SOIC ICs. I got a good price on 20 thou (0.5mm) tools and the increased strength has helped my cause much more than
I expected. The larger tool has 156% the area of the 16 thou tool, hard to credit such a small variation can have such
a dramatic effect.

As I've mentioned I use a software tool called Autoleveller and that has resulted in very very much more precise machining
thereby minimising the amount of fibreglass that gets cut with major increase in tool life. Likewise when I started using
flood cooling, mainly for chip evacuation I got a 20-30 fold increase in tool life.

While these techniques probably will not be useful to you given that you are cutting wood I mention them as examples of small
changes that have had dramatic effects. Keep experimenting, eventually you'll find the right combination that maximises what
you are doing. You'll need a quite a few tools to experiment with. When I get home I'll flick you drillmans EBay store,
Kyocera Tycom tools at very very sharp prices, I buy the vast majority of my micro-tools from him.

Download a trial copy of HSMAdvisor, very useful. Surface speeds are critical parameters particularly in metals. You can get away
with less but very seldom more than recommended speed. With such a small diameter tool you'll never get even close to the
recommended surface speed, the best you can do is spin it as fast as you can. Is your spindle rated to 24000 rpm?
If so why pussy foot around spinning it at less than max, do you disbelieve the spec?

Craig
My wife left with my best friend...
     and I miss him!

Offline dq828

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Re: Acceleration Settings
« Reply #11 on: November 30, 2017, 10:00:59 PM »
Craig

In my first post I say "I have relinquished to some degree, in that I have enlarged the engraving and bought the smallest straight wood bit I could find being a Amana 46229 DOWN CUT 0.031".

I moved up from the 0.02"bit because I couldnot find one that size specifically made for timber. Thanks for the advice I'll have a look at HSMAdviser and I'd be keen to get the link for the Ebay store as you mentioned.

I think I'm just getting old as I shy away from pushing anything to the max anyone :)

Thanks again
Re: Acceleration Settings
« Reply #12 on: December 01, 2017, 12:54:03 AM »
Hi,
there's no doubt about it small diameter tools are a challenge. If you can go to a larger size it will save you some grief.

I liked HSMAvdisor so much I bought it. Wide range of materials, a library of tools, includes power and flexure calculations and torsional flexure as well.

http://stores.ebay.com/carbideplus/

Dubious that you'll save anything by backing off max speed, the tool is that small the power requirement is virtually nill. You might save having the bearings
spin that fast however if you back off to 18000 rpm you'll have to run 25% longer to do the job. Are you gaining anything?

Craig
My wife left with my best friend...
     and I miss him!

Offline dq828

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Re: Acceleration Settings
« Reply #13 on: December 01, 2017, 02:47:41 AM »
Only piece of mind :)

I can afford to break a few at that price, thanks.

David
Re: Acceleration Settings
« Reply #14 on: December 01, 2017, 12:51:06 PM »
Hi David,
yes drillmans prices are good. The last time I got some he had an over supply of 0.5mm tools and was selling them cheap for $2.60 USD each.
I got 30, wish I'd bought more now. I am getting good life out of tools now, a far cry from what it was like when I started.

Craig
My wife left with my best friend...
     and I miss him!

Offline dq828

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Re: Acceleration Settings
« Reply #15 on: December 04, 2017, 06:13:03 AM »
I now see what you mean, I have downloaded the G-Wizard trial and from what I can tell so far you need a spindle that turns at light speed to get the SFM thats recommended :)
Re: Acceleration Settings
« Reply #16 on: December 04, 2017, 03:20:54 PM »
Hi,
my general strategy for tools is to work them near their maximum. With small diameter tools like these I can't
spin them fast enough and also they are weak, excess cutting speed/chip load will break them, caution is required.

With larger tools I try to stick to recommended speed and feeds with plenty of engagement. You can treat them
with 'kid gloves' but the the job takes that long that any saving in tool life is offset or even negated by taking that
much longer.

Craig
My wife left with my best friend...
     and I miss him!